[v5,3/7] drm/i915/tgl: Select master transcoder for MST stream
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Message ID 20191220152954.83276-3-jose.souza@intel.com
State New
Headers show
Series
  • [v5,1/7] drm/i915: Introduce intel_crtc_state_alloc()
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Commit Message

Souza, Jose Dec. 20, 2019, 3:29 p.m. UTC
On TGL the blending of all the streams have moved from DDI to
transcoder, so now every transcoder working over the same MST port must
send its stream to a master transcoder and master will send to DDI
respecting the time slots.

So here adding all the CRTCs that shares the same MST stream if
needed and computing their state again, it will pick the lowest
pipe/transcoder among the ones in the same stream to be master.

Most of the time skl_commit_modeset_enables() enables pipes in a
crescent order but due DDB overlapping it might not happen, this
scenarios will be handled in the next patch.

v2:
- Using recently added intel_crtc_state_reset() to set
mst_master_transcoder to invalid transcoder for all non gen12 & MST
code paths
- Setting lowest pipe/transcoder as master, previously it was the
first one but setting a predictable one will help in future MST e
port sync integration
- Moving to intel type as much as we can

v3:
- Now intel_dp_mst_master_trans_compute() returns the MST master transcoder
- Replaced stdbool.h by linux/types.h
- Skip the connector being checked in
intel_dp_mst_atomic_master_trans_check()
- Using pipe instead of transcoder to compute MST master

v4:
- renamed connector_state to conn_state

v5:
- Improved the parameters of intel_dp_mst_master_trans_compute() to
simply code
- Added call drm_atomic_add_affected_planes() in
intel_dp_mst_atomic_master_trans_check() as helper could not do it
for us
- Removed "if (ret)" left over from v3 changes

BSpec: 50493
BSpec: 49190
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
---
 drivers/gpu/drm/i915/display/intel_atomic.c   |  14 ++
 drivers/gpu/drm/i915/display/intel_atomic.h   |   4 +
 drivers/gpu/drm/i915/display/intel_ddi.c      |  14 +-
 drivers/gpu/drm/i915/display/intel_display.c  |  12 +-
 .../drm/i915/display/intel_display_types.h    |   3 +
 drivers/gpu/drm/i915/display/intel_dp_mst.c   | 140 ++++++++++++++++--
 drivers/gpu/drm/i915/display/intel_dp_mst.h   |   5 +
 7 files changed, 179 insertions(+), 13 deletions(-)

Comments

Ville Syrjala Dec. 20, 2019, 3:47 p.m. UTC | #1
On Fri, Dec 20, 2019 at 07:29:50AM -0800, José Roberto de Souza wrote:
> On TGL the blending of all the streams have moved from DDI to
> transcoder, so now every transcoder working over the same MST port must
> send its stream to a master transcoder and master will send to DDI
> respecting the time slots.
> 
> So here adding all the CRTCs that shares the same MST stream if
> needed and computing their state again, it will pick the lowest
> pipe/transcoder among the ones in the same stream to be master.
> 
> Most of the time skl_commit_modeset_enables() enables pipes in a
> crescent order but due DDB overlapping it might not happen, this
> scenarios will be handled in the next patch.
> 
> v2:
> - Using recently added intel_crtc_state_reset() to set
> mst_master_transcoder to invalid transcoder for all non gen12 & MST
> code paths
> - Setting lowest pipe/transcoder as master, previously it was the
> first one but setting a predictable one will help in future MST e
> port sync integration
> - Moving to intel type as much as we can
> 
> v3:
> - Now intel_dp_mst_master_trans_compute() returns the MST master transcoder
> - Replaced stdbool.h by linux/types.h
> - Skip the connector being checked in
> intel_dp_mst_atomic_master_trans_check()
> - Using pipe instead of transcoder to compute MST master
> 
> v4:
> - renamed connector_state to conn_state
> 
> v5:
> - Improved the parameters of intel_dp_mst_master_trans_compute() to
> simply code
> - Added call drm_atomic_add_affected_planes() in
> intel_dp_mst_atomic_master_trans_check() as helper could not do it
> for us
> - Removed "if (ret)" left over from v3 changes
> 
> BSpec: 50493
> BSpec: 49190
> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_atomic.c   |  14 ++
>  drivers/gpu/drm/i915/display/intel_atomic.h   |   4 +
>  drivers/gpu/drm/i915/display/intel_ddi.c      |  14 +-
>  drivers/gpu/drm/i915/display/intel_display.c  |  12 +-
>  .../drm/i915/display/intel_display_types.h    |   3 +
>  drivers/gpu/drm/i915/display/intel_dp_mst.c   | 140 ++++++++++++++++--
>  drivers/gpu/drm/i915/display/intel_dp_mst.h   |   5 +
>  7 files changed, 179 insertions(+), 13 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c
> index b7dda18b6f29..0eb973f65977 100644
> --- a/drivers/gpu/drm/i915/display/intel_atomic.c
> +++ b/drivers/gpu/drm/i915/display/intel_atomic.c
> @@ -192,6 +192,20 @@ intel_connector_needs_modeset(struct intel_atomic_state *state,
>  									    new_conn_state->crtc)));
>  }
>  
> +struct intel_digital_connector_state *
> +intel_atomic_get_digital_connector_state(struct intel_atomic_state *state,
> +					 struct intel_connector *connector)
> +{
> +	struct drm_connector_state *conn_state;
> +
> +	conn_state = drm_atomic_get_connector_state(&state->base,
> +						    &connector->base);
> +	if (IS_ERR(conn_state))
> +		return ERR_CAST(conn_state);
> +
> +	return to_intel_digital_connector_state(conn_state);
> +}
> +
>  /**
>   * intel_crtc_duplicate_state - duplicate crtc state
>   * @crtc: drm crtc
> diff --git a/drivers/gpu/drm/i915/display/intel_atomic.h b/drivers/gpu/drm/i915/display/intel_atomic.h
> index a7d1a8576c48..74c749dbfb4f 100644
> --- a/drivers/gpu/drm/i915/display/intel_atomic.h
> +++ b/drivers/gpu/drm/i915/display/intel_atomic.h
> @@ -17,6 +17,7 @@ struct drm_device;
>  struct drm_i915_private;
>  struct drm_property;
>  struct intel_atomic_state;
> +struct intel_connector;
>  struct intel_crtc;
>  struct intel_crtc_state;
>  
> @@ -34,6 +35,9 @@ struct drm_connector_state *
>  intel_digital_connector_duplicate_state(struct drm_connector *connector);
>  bool intel_connector_needs_modeset(struct intel_atomic_state *state,
>  				   struct drm_connector *connector);
> +struct intel_digital_connector_state *
> +intel_atomic_get_digital_connector_state(struct intel_atomic_state *state,
> +					 struct intel_connector *connector);
>  
>  struct drm_crtc_state *intel_crtc_duplicate_state(struct drm_crtc *crtc);
>  void intel_crtc_destroy_state(struct drm_crtc *crtc,
> diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
> index c9ba7d7f3787..c3ac950e79a8 100644
> --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> @@ -1899,8 +1899,13 @@ intel_ddi_transcoder_func_reg_val_get(const struct intel_crtc_state *crtc_state)
>  		temp |= TRANS_DDI_MODE_SELECT_DP_MST;
>  		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
>  
> -		if (INTEL_GEN(dev_priv) >= 12)
> -			temp |= TRANS_DDI_MST_TRANSPORT_SELECT(crtc_state->cpu_transcoder);
> +		if (INTEL_GEN(dev_priv) >= 12) {
> +			enum transcoder master;
> +
> +			master = crtc_state->mst_master_transcoder;
> +			WARN_ON(master == INVALID_TRANSCODER);
> +			temp |= TRANS_DDI_MST_TRANSPORT_SELECT(master);
> +		}
>  	} else {
>  		temp |= TRANS_DDI_MODE_SELECT_DP_SST;
>  		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
> @@ -4405,6 +4410,11 @@ void intel_ddi_get_config(struct intel_encoder *encoder,
>  		pipe_config->output_types |= BIT(INTEL_OUTPUT_DP_MST);
>  		pipe_config->lane_count =
>  			((temp & DDI_PORT_WIDTH_MASK) >> DDI_PORT_WIDTH_SHIFT) + 1;
> +
> +		if (INTEL_GEN(dev_priv) >= 12)
> +			pipe_config->mst_master_transcoder =
> +					REG_FIELD_GET(TRANS_DDI_MST_TRANSPORT_SELECT_MASK, temp);
> +
>  		intel_dp_get_m_n(intel_crtc, pipe_config);
>  		break;
>  	default:
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index fc77829ea958..eb97ad562c96 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -46,6 +46,7 @@
>  #include "display/intel_crt.h"
>  #include "display/intel_ddi.h"
>  #include "display/intel_dp.h"
> +#include "display/intel_dp_mst.h"
>  #include "display/intel_dsi.h"
>  #include "display/intel_dvo.h"
>  #include "display/intel_gmbus.h"
> @@ -11627,6 +11628,7 @@ static void intel_crtc_state_reset(struct intel_crtc_state *crtc_state,
>  	crtc_state->hsw_workaround_pipe = INVALID_PIPE;
>  	crtc_state->output_format = INTEL_OUTPUT_FORMAT_INVALID;
>  	crtc_state->scaler_state.scaler_id = -1;
> +	crtc_state->mst_master_transcoder = INVALID_TRANSCODER;
>  }
>  
>  static struct intel_crtc_state *intel_crtc_state_alloc(struct intel_crtc *crtc)
> @@ -12484,6 +12486,9 @@ static void intel_dump_pipe_config(const struct intel_crtc_state *pipe_config,
>  			      pipe_config->csc_mode, pipe_config->gamma_mode,
>  			      pipe_config->gamma_enable, pipe_config->csc_enable);
>  
> +	DRM_DEBUG_KMS("MST master transcoder: %s\n",
> +		      transcoder_name(pipe_config->mst_master_transcoder));
> +
>  dump_planes:
>  	if (!state)
>  		return;
> @@ -13264,6 +13269,8 @@ intel_pipe_config_compare(const struct intel_crtc_state *current_config,
>  	PIPE_CONF_CHECK_I(dsc.dsc_split);
>  	PIPE_CONF_CHECK_I(dsc.compressed_bpp);
>  
> +	PIPE_CONF_CHECK_I(mst_master_transcoder);
> +
>  #undef PIPE_CONF_CHECK_X
>  #undef PIPE_CONF_CHECK_I
>  #undef PIPE_CONF_CHECK_BOOL
> @@ -14348,7 +14355,7 @@ static void intel_commit_modeset_disables(struct intel_atomic_state *state)
>  	u32 handled = 0;
>  	int i;
>  
> -	/* Only disable port sync slaves */
> +	/* Only disable port sync and MST slaves */
>  	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
>  					    new_crtc_state, i) {
>  		if (!needs_modeset(new_crtc_state))
> @@ -14362,7 +14369,8 @@ static void intel_commit_modeset_disables(struct intel_atomic_state *state)
>  		 * slave CRTCs are disabled first and then master CRTC since
>  		 * Slave vblanks are masked till Master Vblanks.
>  		 */
> -		if (!is_trans_port_sync_slave(old_crtc_state))
> +		if (!is_trans_port_sync_slave(old_crtc_state) &&
> +		    !intel_dp_mst_is_slave_trans(old_crtc_state))
>  			continue;
>  
>  		intel_pre_plane_update(state, crtc);
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index 83ea04149b77..630a94892b7b 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -1054,6 +1054,9 @@ struct intel_crtc_state {
>  
>  	/* Bitmask to indicate slaves attached */
>  	u8 sync_mode_slaves_mask;
> +
> +	/* Only valid on TGL+ */
> +	enum transcoder mst_master_transcoder;
>  };
>  
>  struct intel_crtc {
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> index 7aa0975c33b7..a6237da9ac52 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> @@ -87,10 +87,53 @@ static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
>  	return 0;
>  }
>  
> +/*
> + * Iterate over all connectors and return the smallest transcoder in the MST
> + * stream
> + */
> +static enum transcoder
> +intel_dp_mst_master_trans_compute(struct intel_atomic_state *state,
> +				  struct intel_dp *mst_port)
> +{
> +	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> +	struct intel_digital_connector_state *conn_state;
> +	struct intel_connector *connector;
> +	enum pipe ret = I915_MAX_PIPES;
> +	int i;
> +
> +	if (INTEL_GEN(dev_priv) < 12)
> +		return INVALID_TRANSCODER;
> +
> +	for_each_new_intel_connector_in_state(state, connector, conn_state, i) {
> +		struct intel_crtc_state *crtc_state;
> +		struct intel_crtc *crtc;
> +
> +		if (connector->mst_port != mst_port || !conn_state->base.crtc)
> +			continue;
> +
> +		crtc = to_intel_crtc(conn_state->base.crtc);
> +		crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
> +		if (!crtc_state->uapi.active)
> +			continue;
> +
> +		/*
> +		 * Using crtc->pipe because crtc_state->cpu_transcoder is
> +		 * computed, so others CRTCs could have non-computed
> +		 * cpu_transcoder
> +		 */
> +		if (crtc->pipe < ret)
> +			ret = crtc->pipe;
> +	}

Still has the problem that ret==I915_MAX_PIPES if no active crtcs in the
state.

I guess a simple
if (ret == MAX_PIPES)
	return INVALID;
should do here. Or something similar.

With that fixed this is
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Future thoughts based on what I prototyped in
git://github.com/vsyrjala/linux.git port_sync_stuff
would be to simply compute the bitmask of transcoders here, and then
let the caller pick the first with ffs()-1. We could potentially
optimize that approach a bit by only computing each distinct bitmask
only once and storing them temporarult in eg. intel_atomic_state.
Then each encoder would just assign:
mst_master = ffs(precomputed_mst_bitmask[cpu_transcoder]) - 1;


> +
> +	/* Simple cast works because TGL don't have a eDP transcoder */
> +	return (enum transcoder)ret;
> +}
> +
>  static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
>  				       struct intel_crtc_state *pipe_config,
>  				       struct drm_connector_state *conn_state)
>  {
> +	struct intel_atomic_state *state = to_intel_atomic_state(conn_state->state);
>  	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
>  	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
>  	struct intel_dp *intel_dp = &intel_mst->primary->dp;
> @@ -154,24 +197,91 @@ static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
>  
>  	intel_ddi_compute_min_voltage_level(dev_priv, pipe_config);
>  
> +	pipe_config->mst_master_transcoder = intel_dp_mst_master_trans_compute(state, intel_dp);
> +
> +	return 0;
> +}
> +
> +/*
> + * If one of the connectors in a MST stream needs a modeset, mark all CRTCs
> + * that shares the same MST stream as mode changed,
> + * intel_modeset_pipe_config()+intel_crtc_check_fastset() will take care to do
> + * a fastset when possible.
> + */
> +static int
> +intel_dp_mst_atomic_master_trans_check(struct intel_connector *connector,
> +				       struct intel_atomic_state *state)
> +{
> +	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> +	struct drm_connector_list_iter connector_list_iter;
> +	struct intel_connector *connector_iter;
> +
> +	if (INTEL_GEN(dev_priv) < 12)
> +		return  0;
> +
> +	if (!intel_connector_needs_modeset(state, &connector->base))
> +		return 0;
> +
> +	drm_connector_list_iter_begin(&dev_priv->drm, &connector_list_iter);
> +	for_each_intel_connector_iter(connector_iter, &connector_list_iter) {
> +		struct intel_digital_connector_state *conn_iter_state;
> +		struct intel_crtc_state *crtc_state;
> +		struct intel_crtc *crtc;
> +		int ret;
> +
> +		if (connector_iter->mst_port != connector->mst_port ||
> +		    connector_iter == connector)
> +			continue;
> +
> +		conn_iter_state = intel_atomic_get_digital_connector_state(state,
> +									   connector_iter);
> +		if (IS_ERR(conn_iter_state)) {
> +			drm_connector_list_iter_end(&connector_list_iter);
> +			return PTR_ERR(conn_iter_state);
> +		}
> +
> +		if (!conn_iter_state->base.crtc)
> +			continue;
> +
> +		crtc = to_intel_crtc(conn_iter_state->base.crtc);
> +		crtc_state = intel_atomic_get_crtc_state(&state->base, crtc);
> +		if (IS_ERR(crtc_state)) {
> +			drm_connector_list_iter_end(&connector_list_iter);
> +			return PTR_ERR(crtc_state);
> +		}
> +
> +		ret = drm_atomic_add_affected_planes(&state->base, &crtc->base);
> +		if (ret) {
> +			drm_connector_list_iter_end(&connector_list_iter);
> +			return ret;
> +		}
> +		crtc_state->uapi.mode_changed = true;
> +	}
> +	drm_connector_list_iter_end(&connector_list_iter);
> +
>  	return 0;
>  }
>  
>  static int
>  intel_dp_mst_atomic_check(struct drm_connector *connector,
> -			  struct drm_atomic_state *state)
> +			  struct drm_atomic_state *_state)
>  {
> +	struct intel_atomic_state *state = to_intel_atomic_state(_state);
>  	struct drm_connector_state *new_conn_state =
> -		drm_atomic_get_new_connector_state(state, connector);
> +		drm_atomic_get_new_connector_state(&state->base, connector);
>  	struct drm_connector_state *old_conn_state =
> -		drm_atomic_get_old_connector_state(state, connector);
> +		drm_atomic_get_old_connector_state(&state->base, connector);
>  	struct intel_connector *intel_connector =
>  		to_intel_connector(connector);
>  	struct drm_crtc *new_crtc = new_conn_state->crtc;
>  	struct drm_dp_mst_topology_mgr *mgr;
>  	int ret;
>  
> -	ret = intel_digital_connector_atomic_check(connector, state);
> +	ret = intel_digital_connector_atomic_check(connector, &state->base);
> +	if (ret)
> +		return ret;
> +
> +	ret = intel_dp_mst_atomic_master_trans_check(intel_connector, state);
>  	if (ret)
>  		return ret;
>  
> @@ -182,12 +292,9 @@ intel_dp_mst_atomic_check(struct drm_connector *connector,
>  	 * connector
>  	 */
>  	if (new_crtc) {
> -		struct intel_atomic_state *intel_state =
> -			to_intel_atomic_state(state);
>  		struct intel_crtc *intel_crtc = to_intel_crtc(new_crtc);
>  		struct intel_crtc_state *crtc_state =
> -			intel_atomic_get_new_crtc_state(intel_state,
> -							intel_crtc);
> +			intel_atomic_get_new_crtc_state(state, intel_crtc);
>  
>  		if (!crtc_state ||
>  		    !drm_atomic_crtc_needs_modeset(&crtc_state->uapi) ||
> @@ -196,7 +303,7 @@ intel_dp_mst_atomic_check(struct drm_connector *connector,
>  	}
>  
>  	mgr = &enc_to_mst(old_conn_state->best_encoder)->primary->dp.mst_mgr;
> -	ret = drm_dp_atomic_release_vcpi_slots(state, mgr,
> +	ret = drm_dp_atomic_release_vcpi_slots(&state->base, mgr,
>  					       intel_connector->port);
>  
>  	return ret;
> @@ -240,6 +347,8 @@ static void intel_mst_post_disable_dp(struct intel_encoder *encoder,
>  
>  	intel_dp->active_mst_links--;
>  	last_mst_stream = intel_dp->active_mst_links == 0;
> +	WARN_ON(INTEL_GEN(dev_priv) >= 12 && last_mst_stream &&
> +		!intel_dp_mst_is_master_trans(old_crtc_state));
>  
>  	intel_crtc_vblank_off(old_crtc_state);
>  
> @@ -317,6 +426,8 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
>  	connector->encoder = encoder;
>  	intel_mst->connector = connector;
>  	first_mst_stream = intel_dp->active_mst_links == 0;
> +	WARN_ON(INTEL_GEN(dev_priv) >= 12 && first_mst_stream &&
> +		!intel_dp_mst_is_master_trans(pipe_config));
>  
>  	DRM_DEBUG_KMS("active links %d\n", intel_dp->active_mst_links);
>  
> @@ -722,3 +833,14 @@ intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port)
>  	drm_dp_mst_topology_mgr_destroy(&intel_dp->mst_mgr);
>  	/* encoders will get killed by normal cleanup */
>  }
> +
> +bool intel_dp_mst_is_master_trans(const struct intel_crtc_state *crtc_state)
> +{
> +	return crtc_state->mst_master_transcoder == crtc_state->cpu_transcoder;
> +}
> +
> +bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state *crtc_state)
> +{
> +	return crtc_state->mst_master_transcoder != INVALID_TRANSCODER &&
> +	       crtc_state->mst_master_transcoder != crtc_state->cpu_transcoder;
> +}
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.h b/drivers/gpu/drm/i915/display/intel_dp_mst.h
> index f660ad80db04..854724f68f09 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_mst.h
> +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.h
> @@ -6,10 +6,15 @@
>  #ifndef __INTEL_DP_MST_H__
>  #define __INTEL_DP_MST_H__
>  
> +#include <linux/types.h>
> +
>  struct intel_digital_port;
> +struct intel_crtc_state;
>  
>  int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id);
>  void intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port);
>  int intel_dp_mst_encoder_active_links(struct intel_digital_port *intel_dig_port);
> +bool intel_dp_mst_is_master_trans(const struct intel_crtc_state *crtc_state);
> +bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state *crtc_state);
>  
>  #endif /* __INTEL_DP_MST_H__ */
> -- 
> 2.24.1
Souza, Jose Dec. 20, 2019, 4:53 p.m. UTC | #2
On Fri, 2019-12-20 at 17:47 +0200, Ville Syrjälä wrote:
> On Fri, Dec 20, 2019 at 07:29:50AM -0800, José Roberto de Souza
> wrote:
> > On TGL the blending of all the streams have moved from DDI to
> > transcoder, so now every transcoder working over the same MST port
> > must
> > send its stream to a master transcoder and master will send to DDI
> > respecting the time slots.
> > 
> > So here adding all the CRTCs that shares the same MST stream if
> > needed and computing their state again, it will pick the lowest
> > pipe/transcoder among the ones in the same stream to be master.
> > 
> > Most of the time skl_commit_modeset_enables() enables pipes in a
> > crescent order but due DDB overlapping it might not happen, this
> > scenarios will be handled in the next patch.
> > 
> > v2:
> > - Using recently added intel_crtc_state_reset() to set
> > mst_master_transcoder to invalid transcoder for all non gen12 & MST
> > code paths
> > - Setting lowest pipe/transcoder as master, previously it was the
> > first one but setting a predictable one will help in future MST e
> > port sync integration
> > - Moving to intel type as much as we can
> > 
> > v3:
> > - Now intel_dp_mst_master_trans_compute() returns the MST master
> > transcoder
> > - Replaced stdbool.h by linux/types.h
> > - Skip the connector being checked in
> > intel_dp_mst_atomic_master_trans_check()
> > - Using pipe instead of transcoder to compute MST master
> > 
> > v4:
> > - renamed connector_state to conn_state
> > 
> > v5:
> > - Improved the parameters of intel_dp_mst_master_trans_compute() to
> > simply code
> > - Added call drm_atomic_add_affected_planes() in
> > intel_dp_mst_atomic_master_trans_check() as helper could not do it
> > for us
> > - Removed "if (ret)" left over from v3 changes
> > 
> > BSpec: 50493
> > BSpec: 49190
> > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> > Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
> > ---
> >  drivers/gpu/drm/i915/display/intel_atomic.c   |  14 ++
> >  drivers/gpu/drm/i915/display/intel_atomic.h   |   4 +
> >  drivers/gpu/drm/i915/display/intel_ddi.c      |  14 +-
> >  drivers/gpu/drm/i915/display/intel_display.c  |  12 +-
> >  .../drm/i915/display/intel_display_types.h    |   3 +
> >  drivers/gpu/drm/i915/display/intel_dp_mst.c   | 140
> > ++++++++++++++++--
> >  drivers/gpu/drm/i915/display/intel_dp_mst.h   |   5 +
> >  7 files changed, 179 insertions(+), 13 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c
> > b/drivers/gpu/drm/i915/display/intel_atomic.c
> > index b7dda18b6f29..0eb973f65977 100644
> > --- a/drivers/gpu/drm/i915/display/intel_atomic.c
> > +++ b/drivers/gpu/drm/i915/display/intel_atomic.c
> > @@ -192,6 +192,20 @@ intel_connector_needs_modeset(struct
> > intel_atomic_state *state,
> >  									
> >     new_conn_state->crtc)));
> >  }
> >  
> > +struct intel_digital_connector_state *
> > +intel_atomic_get_digital_connector_state(struct intel_atomic_state
> > *state,
> > +					 struct intel_connector
> > *connector)
> > +{
> > +	struct drm_connector_state *conn_state;
> > +
> > +	conn_state = drm_atomic_get_connector_state(&state->base,
> > +						    &connector->base);
> > +	if (IS_ERR(conn_state))
> > +		return ERR_CAST(conn_state);
> > +
> > +	return to_intel_digital_connector_state(conn_state);
> > +}
> > +
> >  /**
> >   * intel_crtc_duplicate_state - duplicate crtc state
> >   * @crtc: drm crtc
> > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.h
> > b/drivers/gpu/drm/i915/display/intel_atomic.h
> > index a7d1a8576c48..74c749dbfb4f 100644
> > --- a/drivers/gpu/drm/i915/display/intel_atomic.h
> > +++ b/drivers/gpu/drm/i915/display/intel_atomic.h
> > @@ -17,6 +17,7 @@ struct drm_device;
> >  struct drm_i915_private;
> >  struct drm_property;
> >  struct intel_atomic_state;
> > +struct intel_connector;
> >  struct intel_crtc;
> >  struct intel_crtc_state;
> >  
> > @@ -34,6 +35,9 @@ struct drm_connector_state *
> >  intel_digital_connector_duplicate_state(struct drm_connector
> > *connector);
> >  bool intel_connector_needs_modeset(struct intel_atomic_state
> > *state,
> >  				   struct drm_connector *connector);
> > +struct intel_digital_connector_state *
> > +intel_atomic_get_digital_connector_state(struct intel_atomic_state
> > *state,
> > +					 struct intel_connector
> > *connector);
> >  
> >  struct drm_crtc_state *intel_crtc_duplicate_state(struct drm_crtc
> > *crtc);
> >  void intel_crtc_destroy_state(struct drm_crtc *crtc,
> > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> > b/drivers/gpu/drm/i915/display/intel_ddi.c
> > index c9ba7d7f3787..c3ac950e79a8 100644
> > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > @@ -1899,8 +1899,13 @@ intel_ddi_transcoder_func_reg_val_get(const
> > struct intel_crtc_state *crtc_state)
> >  		temp |= TRANS_DDI_MODE_SELECT_DP_MST;
> >  		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
> >  
> > -		if (INTEL_GEN(dev_priv) >= 12)
> > -			temp |=
> > TRANS_DDI_MST_TRANSPORT_SELECT(crtc_state->cpu_transcoder);
> > +		if (INTEL_GEN(dev_priv) >= 12) {
> > +			enum transcoder master;
> > +
> > +			master = crtc_state->mst_master_transcoder;
> > +			WARN_ON(master == INVALID_TRANSCODER);
> > +			temp |= TRANS_DDI_MST_TRANSPORT_SELECT(master);
> > +		}
> >  	} else {
> >  		temp |= TRANS_DDI_MODE_SELECT_DP_SST;
> >  		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
> > @@ -4405,6 +4410,11 @@ void intel_ddi_get_config(struct
> > intel_encoder *encoder,
> >  		pipe_config->output_types |= BIT(INTEL_OUTPUT_DP_MST);
> >  		pipe_config->lane_count =
> >  			((temp & DDI_PORT_WIDTH_MASK) >>
> > DDI_PORT_WIDTH_SHIFT) + 1;
> > +
> > +		if (INTEL_GEN(dev_priv) >= 12)
> > +			pipe_config->mst_master_transcoder =
> > +					REG_FIELD_GET(TRANS_DDI_MST_TRA
> > NSPORT_SELECT_MASK, temp);
> > +
> >  		intel_dp_get_m_n(intel_crtc, pipe_config);
> >  		break;
> >  	default:
> > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > b/drivers/gpu/drm/i915/display/intel_display.c
> > index fc77829ea958..eb97ad562c96 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > @@ -46,6 +46,7 @@
> >  #include "display/intel_crt.h"
> >  #include "display/intel_ddi.h"
> >  #include "display/intel_dp.h"
> > +#include "display/intel_dp_mst.h"
> >  #include "display/intel_dsi.h"
> >  #include "display/intel_dvo.h"
> >  #include "display/intel_gmbus.h"
> > @@ -11627,6 +11628,7 @@ static void intel_crtc_state_reset(struct
> > intel_crtc_state *crtc_state,
> >  	crtc_state->hsw_workaround_pipe = INVALID_PIPE;
> >  	crtc_state->output_format = INTEL_OUTPUT_FORMAT_INVALID;
> >  	crtc_state->scaler_state.scaler_id = -1;
> > +	crtc_state->mst_master_transcoder = INVALID_TRANSCODER;
> >  }
> >  
> >  static struct intel_crtc_state *intel_crtc_state_alloc(struct
> > intel_crtc *crtc)
> > @@ -12484,6 +12486,9 @@ static void intel_dump_pipe_config(const
> > struct intel_crtc_state *pipe_config,
> >  			      pipe_config->csc_mode, pipe_config-
> > >gamma_mode,
> >  			      pipe_config->gamma_enable, pipe_config-
> > >csc_enable);
> >  
> > +	DRM_DEBUG_KMS("MST master transcoder: %s\n",
> > +		      transcoder_name(pipe_config-
> > >mst_master_transcoder));
> > +
> >  dump_planes:
> >  	if (!state)
> >  		return;
> > @@ -13264,6 +13269,8 @@ intel_pipe_config_compare(const struct
> > intel_crtc_state *current_config,
> >  	PIPE_CONF_CHECK_I(dsc.dsc_split);
> >  	PIPE_CONF_CHECK_I(dsc.compressed_bpp);
> >  
> > +	PIPE_CONF_CHECK_I(mst_master_transcoder);
> > +
> >  #undef PIPE_CONF_CHECK_X
> >  #undef PIPE_CONF_CHECK_I
> >  #undef PIPE_CONF_CHECK_BOOL
> > @@ -14348,7 +14355,7 @@ static void
> > intel_commit_modeset_disables(struct intel_atomic_state *state)
> >  	u32 handled = 0;
> >  	int i;
> >  
> > -	/* Only disable port sync slaves */
> > +	/* Only disable port sync and MST slaves */
> >  	for_each_oldnew_intel_crtc_in_state(state, crtc,
> > old_crtc_state,
> >  					    new_crtc_state, i) {
> >  		if (!needs_modeset(new_crtc_state))
> > @@ -14362,7 +14369,8 @@ static void
> > intel_commit_modeset_disables(struct intel_atomic_state *state)
> >  		 * slave CRTCs are disabled first and then master CRTC
> > since
> >  		 * Slave vblanks are masked till Master Vblanks.
> >  		 */
> > -		if (!is_trans_port_sync_slave(old_crtc_state))
> > +		if (!is_trans_port_sync_slave(old_crtc_state) &&
> > +		    !intel_dp_mst_is_slave_trans(old_crtc_state))
> >  			continue;
> >  
> >  		intel_pre_plane_update(state, crtc);
> > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > index 83ea04149b77..630a94892b7b 100644
> > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > @@ -1054,6 +1054,9 @@ struct intel_crtc_state {
> >  
> >  	/* Bitmask to indicate slaves attached */
> >  	u8 sync_mode_slaves_mask;
> > +
> > +	/* Only valid on TGL+ */
> > +	enum transcoder mst_master_transcoder;
> >  };
> >  
> >  struct intel_crtc {
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > index 7aa0975c33b7..a6237da9ac52 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > @@ -87,10 +87,53 @@ static int
> > intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
> >  	return 0;
> >  }
> >  
> > +/*
> > + * Iterate over all connectors and return the smallest transcoder
> > in the MST
> > + * stream
> > + */
> > +static enum transcoder
> > +intel_dp_mst_master_trans_compute(struct intel_atomic_state
> > *state,
> > +				  struct intel_dp *mst_port)
> > +{
> > +	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> > +	struct intel_digital_connector_state *conn_state;
> > +	struct intel_connector *connector;
> > +	enum pipe ret = I915_MAX_PIPES;
> > +	int i;
> > +
> > +	if (INTEL_GEN(dev_priv) < 12)
> > +		return INVALID_TRANSCODER;
> > +
> > +	for_each_new_intel_connector_in_state(state, connector,
> > conn_state, i) {
> > +		struct intel_crtc_state *crtc_state;
> > +		struct intel_crtc *crtc;
> > +
> > +		if (connector->mst_port != mst_port || !conn_state-
> > >base.crtc)
> > +			continue;
> > +
> > +		crtc = to_intel_crtc(conn_state->base.crtc);
> > +		crtc_state = intel_atomic_get_new_crtc_state(state,
> > crtc);
> > +		if (!crtc_state->uapi.active)
> > +			continue;
> > +
> > +		/*
> > +		 * Using crtc->pipe because crtc_state->cpu_transcoder
> > is
> > +		 * computed, so others CRTCs could have non-computed
> > +		 * cpu_transcoder
> > +		 */
> > +		if (crtc->pipe < ret)
> > +			ret = crtc->pipe;
> > +	}
> 
> Still has the problem that ret==I915_MAX_PIPES if no active crtcs in
> the
> state.
> 
> I guess a simple
> if (ret == MAX_PIPES)
> 	return INVALID;
> should do here. Or something similar.

It would never happen, if it is computing state for this MST connector
it is active, so it can be master. But okay adding it anyways.

> 
> With that fixed this is
> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> Future thoughts based on what I prototyped in
> git://github.com/vsyrjala/linux.git port_sync_stuff
> would be to simply compute the bitmask of transcoders here, and then
> let the caller pick the first with ffs()-1. We could potentially
> optimize that approach a bit by only computing each distinct bitmask
> only once and storing them temporarult in eg. intel_atomic_state.
> Then each encoder would just assign:
> mst_master = ffs(precomputed_mst_bitmask[cpu_transcoder]) - 1;
> 
> 
> > +
> > +	/* Simple cast works because TGL don't have a eDP transcoder */
> > +	return (enum transcoder)ret;
> > +}
> > +
> >  static int intel_dp_mst_compute_config(struct intel_encoder
> > *encoder,
> >  				       struct intel_crtc_state
> > *pipe_config,
> >  				       struct drm_connector_state
> > *conn_state)
> >  {
> > +	struct intel_atomic_state *state =
> > to_intel_atomic_state(conn_state->state);
> >  	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> >  	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder-
> > >base);
> >  	struct intel_dp *intel_dp = &intel_mst->primary->dp;
> > @@ -154,24 +197,91 @@ static int intel_dp_mst_compute_config(struct
> > intel_encoder *encoder,
> >  
> >  	intel_ddi_compute_min_voltage_level(dev_priv, pipe_config);
> >  
> > +	pipe_config->mst_master_transcoder =
> > intel_dp_mst_master_trans_compute(state, intel_dp);
> > +
> > +	return 0;
> > +}
> > +
> > +/*
> > + * If one of the connectors in a MST stream needs a modeset, mark
> > all CRTCs
> > + * that shares the same MST stream as mode changed,
> > + * intel_modeset_pipe_config()+intel_crtc_check_fastset() will
> > take care to do
> > + * a fastset when possible.
> > + */
> > +static int
> > +intel_dp_mst_atomic_master_trans_check(struct intel_connector
> > *connector,
> > +				       struct intel_atomic_state
> > *state)
> > +{
> > +	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> > +	struct drm_connector_list_iter connector_list_iter;
> > +	struct intel_connector *connector_iter;
> > +
> > +	if (INTEL_GEN(dev_priv) < 12)
> > +		return  0;
> > +
> > +	if (!intel_connector_needs_modeset(state, &connector->base))
> > +		return 0;
> > +
> > +	drm_connector_list_iter_begin(&dev_priv->drm,
> > &connector_list_iter);
> > +	for_each_intel_connector_iter(connector_iter,
> > &connector_list_iter) {
> > +		struct intel_digital_connector_state *conn_iter_state;
> > +		struct intel_crtc_state *crtc_state;
> > +		struct intel_crtc *crtc;
> > +		int ret;
> > +
> > +		if (connector_iter->mst_port != connector->mst_port ||
> > +		    connector_iter == connector)
> > +			continue;
> > +
> > +		conn_iter_state =
> > intel_atomic_get_digital_connector_state(state,
> > +									
> >    connector_iter);
> > +		if (IS_ERR(conn_iter_state)) {
> > +			drm_connector_list_iter_end(&connector_list_ite
> > r);
> > +			return PTR_ERR(conn_iter_state);
> > +		}
> > +
> > +		if (!conn_iter_state->base.crtc)
> > +			continue;
> > +
> > +		crtc = to_intel_crtc(conn_iter_state->base.crtc);
> > +		crtc_state = intel_atomic_get_crtc_state(&state->base,
> > crtc);
> > +		if (IS_ERR(crtc_state)) {
> > +			drm_connector_list_iter_end(&connector_list_ite
> > r);
> > +			return PTR_ERR(crtc_state);
> > +		}
> > +
> > +		ret = drm_atomic_add_affected_planes(&state->base,
> > &crtc->base);
> > +		if (ret) {
> > +			drm_connector_list_iter_end(&connector_list_ite
> > r);
> > +			return ret;
> > +		}
> > +		crtc_state->uapi.mode_changed = true;
> > +	}
> > +	drm_connector_list_iter_end(&connector_list_iter);
> > +
> >  	return 0;
> >  }
> >  
> >  static int
> >  intel_dp_mst_atomic_check(struct drm_connector *connector,
> > -			  struct drm_atomic_state *state)
> > +			  struct drm_atomic_state *_state)
> >  {
> > +	struct intel_atomic_state *state =
> > to_intel_atomic_state(_state);
> >  	struct drm_connector_state *new_conn_state =
> > -		drm_atomic_get_new_connector_state(state, connector);
> > +		drm_atomic_get_new_connector_state(&state->base,
> > connector);
> >  	struct drm_connector_state *old_conn_state =
> > -		drm_atomic_get_old_connector_state(state, connector);
> > +		drm_atomic_get_old_connector_state(&state->base,
> > connector);
> >  	struct intel_connector *intel_connector =
> >  		to_intel_connector(connector);
> >  	struct drm_crtc *new_crtc = new_conn_state->crtc;
> >  	struct drm_dp_mst_topology_mgr *mgr;
> >  	int ret;
> >  
> > -	ret = intel_digital_connector_atomic_check(connector, state);
> > +	ret = intel_digital_connector_atomic_check(connector, &state-
> > >base);
> > +	if (ret)
> > +		return ret;
> > +
> > +	ret = intel_dp_mst_atomic_master_trans_check(intel_connector,
> > state);
> >  	if (ret)
> >  		return ret;
> >  
> > @@ -182,12 +292,9 @@ intel_dp_mst_atomic_check(struct drm_connector
> > *connector,
> >  	 * connector
> >  	 */
> >  	if (new_crtc) {
> > -		struct intel_atomic_state *intel_state =
> > -			to_intel_atomic_state(state);
> >  		struct intel_crtc *intel_crtc =
> > to_intel_crtc(new_crtc);
> >  		struct intel_crtc_state *crtc_state =
> > -			intel_atomic_get_new_crtc_state(intel_state,
> > -							intel_crtc);
> > +			intel_atomic_get_new_crtc_state(state,
> > intel_crtc);
> >  
> >  		if (!crtc_state ||
> >  		    !drm_atomic_crtc_needs_modeset(&crtc_state->uapi)
> > ||
> > @@ -196,7 +303,7 @@ intel_dp_mst_atomic_check(struct drm_connector
> > *connector,
> >  	}
> >  
> >  	mgr = &enc_to_mst(old_conn_state->best_encoder)->primary-
> > >dp.mst_mgr;
> > -	ret = drm_dp_atomic_release_vcpi_slots(state, mgr,
> > +	ret = drm_dp_atomic_release_vcpi_slots(&state->base, mgr,
> >  					       intel_connector->port);
> >  
> >  	return ret;
> > @@ -240,6 +347,8 @@ static void intel_mst_post_disable_dp(struct
> > intel_encoder *encoder,
> >  
> >  	intel_dp->active_mst_links--;
> >  	last_mst_stream = intel_dp->active_mst_links == 0;
> > +	WARN_ON(INTEL_GEN(dev_priv) >= 12 && last_mst_stream &&
> > +		!intel_dp_mst_is_master_trans(old_crtc_state));
> >  
> >  	intel_crtc_vblank_off(old_crtc_state);
> >  
> > @@ -317,6 +426,8 @@ static void intel_mst_pre_enable_dp(struct
> > intel_encoder *encoder,
> >  	connector->encoder = encoder;
> >  	intel_mst->connector = connector;
> >  	first_mst_stream = intel_dp->active_mst_links == 0;
> > +	WARN_ON(INTEL_GEN(dev_priv) >= 12 && first_mst_stream &&
> > +		!intel_dp_mst_is_master_trans(pipe_config));
> >  
> >  	DRM_DEBUG_KMS("active links %d\n", intel_dp->active_mst_links);
> >  
> > @@ -722,3 +833,14 @@ intel_dp_mst_encoder_cleanup(struct
> > intel_digital_port *intel_dig_port)
> >  	drm_dp_mst_topology_mgr_destroy(&intel_dp->mst_mgr);
> >  	/* encoders will get killed by normal cleanup */
> >  }
> > +
> > +bool intel_dp_mst_is_master_trans(const struct intel_crtc_state
> > *crtc_state)
> > +{
> > +	return crtc_state->mst_master_transcoder == crtc_state-
> > >cpu_transcoder;
> > +}
> > +
> > +bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state
> > *crtc_state)
> > +{
> > +	return crtc_state->mst_master_transcoder != INVALID_TRANSCODER
> > &&
> > +	       crtc_state->mst_master_transcoder != crtc_state-
> > >cpu_transcoder;
> > +}
> > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.h
> > b/drivers/gpu/drm/i915/display/intel_dp_mst.h
> > index f660ad80db04..854724f68f09 100644
> > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.h
> > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.h
> > @@ -6,10 +6,15 @@
> >  #ifndef __INTEL_DP_MST_H__
> >  #define __INTEL_DP_MST_H__
> >  
> > +#include <linux/types.h>
> > +
> >  struct intel_digital_port;
> > +struct intel_crtc_state;
> >  
> >  int intel_dp_mst_encoder_init(struct intel_digital_port
> > *intel_dig_port, int conn_id);
> >  void intel_dp_mst_encoder_cleanup(struct intel_digital_port
> > *intel_dig_port);
> >  int intel_dp_mst_encoder_active_links(struct intel_digital_port
> > *intel_dig_port);
> > +bool intel_dp_mst_is_master_trans(const struct intel_crtc_state
> > *crtc_state);
> > +bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state
> > *crtc_state);
> >  
> >  #endif /* __INTEL_DP_MST_H__ */
> > -- 
> > 2.24.1
Ville Syrjala Dec. 20, 2019, 5:03 p.m. UTC | #3
On Fri, Dec 20, 2019 at 04:53:22PM +0000, Souza, Jose wrote:
> On Fri, 2019-12-20 at 17:47 +0200, Ville Syrjälä wrote:
> > On Fri, Dec 20, 2019 at 07:29:50AM -0800, José Roberto de Souza
> > wrote:
> > > On TGL the blending of all the streams have moved from DDI to
> > > transcoder, so now every transcoder working over the same MST port
> > > must
> > > send its stream to a master transcoder and master will send to DDI
> > > respecting the time slots.
> > > 
> > > So here adding all the CRTCs that shares the same MST stream if
> > > needed and computing their state again, it will pick the lowest
> > > pipe/transcoder among the ones in the same stream to be master.
> > > 
> > > Most of the time skl_commit_modeset_enables() enables pipes in a
> > > crescent order but due DDB overlapping it might not happen, this
> > > scenarios will be handled in the next patch.
> > > 
> > > v2:
> > > - Using recently added intel_crtc_state_reset() to set
> > > mst_master_transcoder to invalid transcoder for all non gen12 & MST
> > > code paths
> > > - Setting lowest pipe/transcoder as master, previously it was the
> > > first one but setting a predictable one will help in future MST e
> > > port sync integration
> > > - Moving to intel type as much as we can
> > > 
> > > v3:
> > > - Now intel_dp_mst_master_trans_compute() returns the MST master
> > > transcoder
> > > - Replaced stdbool.h by linux/types.h
> > > - Skip the connector being checked in
> > > intel_dp_mst_atomic_master_trans_check()
> > > - Using pipe instead of transcoder to compute MST master
> > > 
> > > v4:
> > > - renamed connector_state to conn_state
> > > 
> > > v5:
> > > - Improved the parameters of intel_dp_mst_master_trans_compute() to
> > > simply code
> > > - Added call drm_atomic_add_affected_planes() in
> > > intel_dp_mst_atomic_master_trans_check() as helper could not do it
> > > for us
> > > - Removed "if (ret)" left over from v3 changes
> > > 
> > > BSpec: 50493
> > > BSpec: 49190
> > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> > > Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/display/intel_atomic.c   |  14 ++
> > >  drivers/gpu/drm/i915/display/intel_atomic.h   |   4 +
> > >  drivers/gpu/drm/i915/display/intel_ddi.c      |  14 +-
> > >  drivers/gpu/drm/i915/display/intel_display.c  |  12 +-
> > >  .../drm/i915/display/intel_display_types.h    |   3 +
> > >  drivers/gpu/drm/i915/display/intel_dp_mst.c   | 140
> > > ++++++++++++++++--
> > >  drivers/gpu/drm/i915/display/intel_dp_mst.h   |   5 +
> > >  7 files changed, 179 insertions(+), 13 deletions(-)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c
> > > b/drivers/gpu/drm/i915/display/intel_atomic.c
> > > index b7dda18b6f29..0eb973f65977 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_atomic.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_atomic.c
> > > @@ -192,6 +192,20 @@ intel_connector_needs_modeset(struct
> > > intel_atomic_state *state,
> > >  									
> > >     new_conn_state->crtc)));
> > >  }
> > >  
> > > +struct intel_digital_connector_state *
> > > +intel_atomic_get_digital_connector_state(struct intel_atomic_state
> > > *state,
> > > +					 struct intel_connector
> > > *connector)
> > > +{
> > > +	struct drm_connector_state *conn_state;
> > > +
> > > +	conn_state = drm_atomic_get_connector_state(&state->base,
> > > +						    &connector->base);
> > > +	if (IS_ERR(conn_state))
> > > +		return ERR_CAST(conn_state);
> > > +
> > > +	return to_intel_digital_connector_state(conn_state);
> > > +}
> > > +
> > >  /**
> > >   * intel_crtc_duplicate_state - duplicate crtc state
> > >   * @crtc: drm crtc
> > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.h
> > > b/drivers/gpu/drm/i915/display/intel_atomic.h
> > > index a7d1a8576c48..74c749dbfb4f 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_atomic.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_atomic.h
> > > @@ -17,6 +17,7 @@ struct drm_device;
> > >  struct drm_i915_private;
> > >  struct drm_property;
> > >  struct intel_atomic_state;
> > > +struct intel_connector;
> > >  struct intel_crtc;
> > >  struct intel_crtc_state;
> > >  
> > > @@ -34,6 +35,9 @@ struct drm_connector_state *
> > >  intel_digital_connector_duplicate_state(struct drm_connector
> > > *connector);
> > >  bool intel_connector_needs_modeset(struct intel_atomic_state
> > > *state,
> > >  				   struct drm_connector *connector);
> > > +struct intel_digital_connector_state *
> > > +intel_atomic_get_digital_connector_state(struct intel_atomic_state
> > > *state,
> > > +					 struct intel_connector
> > > *connector);
> > >  
> > >  struct drm_crtc_state *intel_crtc_duplicate_state(struct drm_crtc
> > > *crtc);
> > >  void intel_crtc_destroy_state(struct drm_crtc *crtc,
> > > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> > > b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > index c9ba7d7f3787..c3ac950e79a8 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > @@ -1899,8 +1899,13 @@ intel_ddi_transcoder_func_reg_val_get(const
> > > struct intel_crtc_state *crtc_state)
> > >  		temp |= TRANS_DDI_MODE_SELECT_DP_MST;
> > >  		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
> > >  
> > > -		if (INTEL_GEN(dev_priv) >= 12)
> > > -			temp |=
> > > TRANS_DDI_MST_TRANSPORT_SELECT(crtc_state->cpu_transcoder);
> > > +		if (INTEL_GEN(dev_priv) >= 12) {
> > > +			enum transcoder master;
> > > +
> > > +			master = crtc_state->mst_master_transcoder;
> > > +			WARN_ON(master == INVALID_TRANSCODER);
> > > +			temp |= TRANS_DDI_MST_TRANSPORT_SELECT(master);
> > > +		}
> > >  	} else {
> > >  		temp |= TRANS_DDI_MODE_SELECT_DP_SST;
> > >  		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
> > > @@ -4405,6 +4410,11 @@ void intel_ddi_get_config(struct
> > > intel_encoder *encoder,
> > >  		pipe_config->output_types |= BIT(INTEL_OUTPUT_DP_MST);
> > >  		pipe_config->lane_count =
> > >  			((temp & DDI_PORT_WIDTH_MASK) >>
> > > DDI_PORT_WIDTH_SHIFT) + 1;
> > > +
> > > +		if (INTEL_GEN(dev_priv) >= 12)
> > > +			pipe_config->mst_master_transcoder =
> > > +					REG_FIELD_GET(TRANS_DDI_MST_TRA
> > > NSPORT_SELECT_MASK, temp);
> > > +
> > >  		intel_dp_get_m_n(intel_crtc, pipe_config);
> > >  		break;
> > >  	default:
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > > b/drivers/gpu/drm/i915/display/intel_display.c
> > > index fc77829ea958..eb97ad562c96 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > @@ -46,6 +46,7 @@
> > >  #include "display/intel_crt.h"
> > >  #include "display/intel_ddi.h"
> > >  #include "display/intel_dp.h"
> > > +#include "display/intel_dp_mst.h"
> > >  #include "display/intel_dsi.h"
> > >  #include "display/intel_dvo.h"
> > >  #include "display/intel_gmbus.h"
> > > @@ -11627,6 +11628,7 @@ static void intel_crtc_state_reset(struct
> > > intel_crtc_state *crtc_state,
> > >  	crtc_state->hsw_workaround_pipe = INVALID_PIPE;
> > >  	crtc_state->output_format = INTEL_OUTPUT_FORMAT_INVALID;
> > >  	crtc_state->scaler_state.scaler_id = -1;
> > > +	crtc_state->mst_master_transcoder = INVALID_TRANSCODER;
> > >  }
> > >  
> > >  static struct intel_crtc_state *intel_crtc_state_alloc(struct
> > > intel_crtc *crtc)
> > > @@ -12484,6 +12486,9 @@ static void intel_dump_pipe_config(const
> > > struct intel_crtc_state *pipe_config,
> > >  			      pipe_config->csc_mode, pipe_config-
> > > >gamma_mode,
> > >  			      pipe_config->gamma_enable, pipe_config-
> > > >csc_enable);
> > >  
> > > +	DRM_DEBUG_KMS("MST master transcoder: %s\n",
> > > +		      transcoder_name(pipe_config-
> > > >mst_master_transcoder));
> > > +
> > >  dump_planes:
> > >  	if (!state)
> > >  		return;
> > > @@ -13264,6 +13269,8 @@ intel_pipe_config_compare(const struct
> > > intel_crtc_state *current_config,
> > >  	PIPE_CONF_CHECK_I(dsc.dsc_split);
> > >  	PIPE_CONF_CHECK_I(dsc.compressed_bpp);
> > >  
> > > +	PIPE_CONF_CHECK_I(mst_master_transcoder);
> > > +
> > >  #undef PIPE_CONF_CHECK_X
> > >  #undef PIPE_CONF_CHECK_I
> > >  #undef PIPE_CONF_CHECK_BOOL
> > > @@ -14348,7 +14355,7 @@ static void
> > > intel_commit_modeset_disables(struct intel_atomic_state *state)
> > >  	u32 handled = 0;
> > >  	int i;
> > >  
> > > -	/* Only disable port sync slaves */
> > > +	/* Only disable port sync and MST slaves */
> > >  	for_each_oldnew_intel_crtc_in_state(state, crtc,
> > > old_crtc_state,
> > >  					    new_crtc_state, i) {
> > >  		if (!needs_modeset(new_crtc_state))
> > > @@ -14362,7 +14369,8 @@ static void
> > > intel_commit_modeset_disables(struct intel_atomic_state *state)
> > >  		 * slave CRTCs are disabled first and then master CRTC
> > > since
> > >  		 * Slave vblanks are masked till Master Vblanks.
> > >  		 */
> > > -		if (!is_trans_port_sync_slave(old_crtc_state))
> > > +		if (!is_trans_port_sync_slave(old_crtc_state) &&
> > > +		    !intel_dp_mst_is_slave_trans(old_crtc_state))
> > >  			continue;
> > >  
> > >  		intel_pre_plane_update(state, crtc);
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > index 83ea04149b77..630a94892b7b 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > @@ -1054,6 +1054,9 @@ struct intel_crtc_state {
> > >  
> > >  	/* Bitmask to indicate slaves attached */
> > >  	u8 sync_mode_slaves_mask;
> > > +
> > > +	/* Only valid on TGL+ */
> > > +	enum transcoder mst_master_transcoder;
> > >  };
> > >  
> > >  struct intel_crtc {
> > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > index 7aa0975c33b7..a6237da9ac52 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > @@ -87,10 +87,53 @@ static int
> > > intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
> > >  	return 0;
> > >  }
> > >  
> > > +/*
> > > + * Iterate over all connectors and return the smallest transcoder
> > > in the MST
> > > + * stream
> > > + */
> > > +static enum transcoder
> > > +intel_dp_mst_master_trans_compute(struct intel_atomic_state
> > > *state,
> > > +				  struct intel_dp *mst_port)
> > > +{
> > > +	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> > > +	struct intel_digital_connector_state *conn_state;
> > > +	struct intel_connector *connector;
> > > +	enum pipe ret = I915_MAX_PIPES;
> > > +	int i;
> > > +
> > > +	if (INTEL_GEN(dev_priv) < 12)
> > > +		return INVALID_TRANSCODER;
> > > +
> > > +	for_each_new_intel_connector_in_state(state, connector,
> > > conn_state, i) {
> > > +		struct intel_crtc_state *crtc_state;
> > > +		struct intel_crtc *crtc;
> > > +
> > > +		if (connector->mst_port != mst_port || !conn_state-
> > > >base.crtc)
> > > +			continue;
> > > +
> > > +		crtc = to_intel_crtc(conn_state->base.crtc);
> > > +		crtc_state = intel_atomic_get_new_crtc_state(state,
> > > crtc);
> > > +		if (!crtc_state->uapi.active)
> > > +			continue;
> > > +
> > > +		/*
> > > +		 * Using crtc->pipe because crtc_state->cpu_transcoder
> > > is
> > > +		 * computed, so others CRTCs could have non-computed
> > > +		 * cpu_transcoder
> > > +		 */
> > > +		if (crtc->pipe < ret)
> > > +			ret = crtc->pipe;
> > > +	}
> > 
> > Still has the problem that ret==I915_MAX_PIPES if no active crtcs in
> > the
> > state.
> > 
> > I guess a simple
> > if (ret == MAX_PIPES)
> > 	return INVALID;
> > should do here. Or something similar.
> 
> It would never happen, if it is computing state for this MST connector
> it is active, so it can be master. But okay adding it anyways.

active != enabled. Pretty sure it will happen.
Ville Syrjala Dec. 20, 2019, 6:43 p.m. UTC | #4
On Fri, Dec 20, 2019 at 07:03:16PM +0200, Ville Syrjälä wrote:
> On Fri, Dec 20, 2019 at 04:53:22PM +0000, Souza, Jose wrote:
> > On Fri, 2019-12-20 at 17:47 +0200, Ville Syrjälä wrote:
> > > On Fri, Dec 20, 2019 at 07:29:50AM -0800, José Roberto de Souza
> > > wrote:
> > > > On TGL the blending of all the streams have moved from DDI to
> > > > transcoder, so now every transcoder working over the same MST port
> > > > must
> > > > send its stream to a master transcoder and master will send to DDI
> > > > respecting the time slots.
> > > > 
> > > > So here adding all the CRTCs that shares the same MST stream if
> > > > needed and computing their state again, it will pick the lowest
> > > > pipe/transcoder among the ones in the same stream to be master.
> > > > 
> > > > Most of the time skl_commit_modeset_enables() enables pipes in a
> > > > crescent order but due DDB overlapping it might not happen, this
> > > > scenarios will be handled in the next patch.
> > > > 
> > > > v2:
> > > > - Using recently added intel_crtc_state_reset() to set
> > > > mst_master_transcoder to invalid transcoder for all non gen12 & MST
> > > > code paths
> > > > - Setting lowest pipe/transcoder as master, previously it was the
> > > > first one but setting a predictable one will help in future MST e
> > > > port sync integration
> > > > - Moving to intel type as much as we can
> > > > 
> > > > v3:
> > > > - Now intel_dp_mst_master_trans_compute() returns the MST master
> > > > transcoder
> > > > - Replaced stdbool.h by linux/types.h
> > > > - Skip the connector being checked in
> > > > intel_dp_mst_atomic_master_trans_check()
> > > > - Using pipe instead of transcoder to compute MST master
> > > > 
> > > > v4:
> > > > - renamed connector_state to conn_state
> > > > 
> > > > v5:
> > > > - Improved the parameters of intel_dp_mst_master_trans_compute() to
> > > > simply code
> > > > - Added call drm_atomic_add_affected_planes() in
> > > > intel_dp_mst_atomic_master_trans_check() as helper could not do it
> > > > for us
> > > > - Removed "if (ret)" left over from v3 changes
> > > > 
> > > > BSpec: 50493
> > > > BSpec: 49190
> > > > Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > > > Cc: Lucas De Marchi <lucas.demarchi@intel.com>
> > > > Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
> > > > ---
> > > >  drivers/gpu/drm/i915/display/intel_atomic.c   |  14 ++
> > > >  drivers/gpu/drm/i915/display/intel_atomic.h   |   4 +
> > > >  drivers/gpu/drm/i915/display/intel_ddi.c      |  14 +-
> > > >  drivers/gpu/drm/i915/display/intel_display.c  |  12 +-
> > > >  .../drm/i915/display/intel_display_types.h    |   3 +
> > > >  drivers/gpu/drm/i915/display/intel_dp_mst.c   | 140
> > > > ++++++++++++++++--
> > > >  drivers/gpu/drm/i915/display/intel_dp_mst.h   |   5 +
> > > >  7 files changed, 179 insertions(+), 13 deletions(-)
> > > > 
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c
> > > > b/drivers/gpu/drm/i915/display/intel_atomic.c
> > > > index b7dda18b6f29..0eb973f65977 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_atomic.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_atomic.c
> > > > @@ -192,6 +192,20 @@ intel_connector_needs_modeset(struct
> > > > intel_atomic_state *state,
> > > >  									
> > > >     new_conn_state->crtc)));
> > > >  }
> > > >  
> > > > +struct intel_digital_connector_state *
> > > > +intel_atomic_get_digital_connector_state(struct intel_atomic_state
> > > > *state,
> > > > +					 struct intel_connector
> > > > *connector)
> > > > +{
> > > > +	struct drm_connector_state *conn_state;
> > > > +
> > > > +	conn_state = drm_atomic_get_connector_state(&state->base,
> > > > +						    &connector->base);
> > > > +	if (IS_ERR(conn_state))
> > > > +		return ERR_CAST(conn_state);
> > > > +
> > > > +	return to_intel_digital_connector_state(conn_state);
> > > > +}
> > > > +
> > > >  /**
> > > >   * intel_crtc_duplicate_state - duplicate crtc state
> > > >   * @crtc: drm crtc
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.h
> > > > b/drivers/gpu/drm/i915/display/intel_atomic.h
> > > > index a7d1a8576c48..74c749dbfb4f 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_atomic.h
> > > > +++ b/drivers/gpu/drm/i915/display/intel_atomic.h
> > > > @@ -17,6 +17,7 @@ struct drm_device;
> > > >  struct drm_i915_private;
> > > >  struct drm_property;
> > > >  struct intel_atomic_state;
> > > > +struct intel_connector;
> > > >  struct intel_crtc;
> > > >  struct intel_crtc_state;
> > > >  
> > > > @@ -34,6 +35,9 @@ struct drm_connector_state *
> > > >  intel_digital_connector_duplicate_state(struct drm_connector
> > > > *connector);
> > > >  bool intel_connector_needs_modeset(struct intel_atomic_state
> > > > *state,
> > > >  				   struct drm_connector *connector);
> > > > +struct intel_digital_connector_state *
> > > > +intel_atomic_get_digital_connector_state(struct intel_atomic_state
> > > > *state,
> > > > +					 struct intel_connector
> > > > *connector);
> > > >  
> > > >  struct drm_crtc_state *intel_crtc_duplicate_state(struct drm_crtc
> > > > *crtc);
> > > >  void intel_crtc_destroy_state(struct drm_crtc *crtc,
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c
> > > > b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > > index c9ba7d7f3787..c3ac950e79a8 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_ddi.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_ddi.c
> > > > @@ -1899,8 +1899,13 @@ intel_ddi_transcoder_func_reg_val_get(const
> > > > struct intel_crtc_state *crtc_state)
> > > >  		temp |= TRANS_DDI_MODE_SELECT_DP_MST;
> > > >  		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
> > > >  
> > > > -		if (INTEL_GEN(dev_priv) >= 12)
> > > > -			temp |=
> > > > TRANS_DDI_MST_TRANSPORT_SELECT(crtc_state->cpu_transcoder);
> > > > +		if (INTEL_GEN(dev_priv) >= 12) {
> > > > +			enum transcoder master;
> > > > +
> > > > +			master = crtc_state->mst_master_transcoder;
> > > > +			WARN_ON(master == INVALID_TRANSCODER);
> > > > +			temp |= TRANS_DDI_MST_TRANSPORT_SELECT(master);
> > > > +		}
> > > >  	} else {
> > > >  		temp |= TRANS_DDI_MODE_SELECT_DP_SST;
> > > >  		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
> > > > @@ -4405,6 +4410,11 @@ void intel_ddi_get_config(struct
> > > > intel_encoder *encoder,
> > > >  		pipe_config->output_types |= BIT(INTEL_OUTPUT_DP_MST);
> > > >  		pipe_config->lane_count =
> > > >  			((temp & DDI_PORT_WIDTH_MASK) >>
> > > > DDI_PORT_WIDTH_SHIFT) + 1;
> > > > +
> > > > +		if (INTEL_GEN(dev_priv) >= 12)
> > > > +			pipe_config->mst_master_transcoder =
> > > > +					REG_FIELD_GET(TRANS_DDI_MST_TRA
> > > > NSPORT_SELECT_MASK, temp);
> > > > +
> > > >  		intel_dp_get_m_n(intel_crtc, pipe_config);
> > > >  		break;
> > > >  	default:
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > > > b/drivers/gpu/drm/i915/display/intel_display.c
> > > > index fc77829ea958..eb97ad562c96 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > > @@ -46,6 +46,7 @@
> > > >  #include "display/intel_crt.h"
> > > >  #include "display/intel_ddi.h"
> > > >  #include "display/intel_dp.h"
> > > > +#include "display/intel_dp_mst.h"
> > > >  #include "display/intel_dsi.h"
> > > >  #include "display/intel_dvo.h"
> > > >  #include "display/intel_gmbus.h"
> > > > @@ -11627,6 +11628,7 @@ static void intel_crtc_state_reset(struct
> > > > intel_crtc_state *crtc_state,
> > > >  	crtc_state->hsw_workaround_pipe = INVALID_PIPE;
> > > >  	crtc_state->output_format = INTEL_OUTPUT_FORMAT_INVALID;
> > > >  	crtc_state->scaler_state.scaler_id = -1;
> > > > +	crtc_state->mst_master_transcoder = INVALID_TRANSCODER;
> > > >  }
> > > >  
> > > >  static struct intel_crtc_state *intel_crtc_state_alloc(struct
> > > > intel_crtc *crtc)
> > > > @@ -12484,6 +12486,9 @@ static void intel_dump_pipe_config(const
> > > > struct intel_crtc_state *pipe_config,
> > > >  			      pipe_config->csc_mode, pipe_config-
> > > > >gamma_mode,
> > > >  			      pipe_config->gamma_enable, pipe_config-
> > > > >csc_enable);
> > > >  
> > > > +	DRM_DEBUG_KMS("MST master transcoder: %s\n",
> > > > +		      transcoder_name(pipe_config-
> > > > >mst_master_transcoder));
> > > > +
> > > >  dump_planes:
> > > >  	if (!state)
> > > >  		return;
> > > > @@ -13264,6 +13269,8 @@ intel_pipe_config_compare(const struct
> > > > intel_crtc_state *current_config,
> > > >  	PIPE_CONF_CHECK_I(dsc.dsc_split);
> > > >  	PIPE_CONF_CHECK_I(dsc.compressed_bpp);
> > > >  
> > > > +	PIPE_CONF_CHECK_I(mst_master_transcoder);
> > > > +
> > > >  #undef PIPE_CONF_CHECK_X
> > > >  #undef PIPE_CONF_CHECK_I
> > > >  #undef PIPE_CONF_CHECK_BOOL
> > > > @@ -14348,7 +14355,7 @@ static void
> > > > intel_commit_modeset_disables(struct intel_atomic_state *state)
> > > >  	u32 handled = 0;
> > > >  	int i;
> > > >  
> > > > -	/* Only disable port sync slaves */
> > > > +	/* Only disable port sync and MST slaves */
> > > >  	for_each_oldnew_intel_crtc_in_state(state, crtc,
> > > > old_crtc_state,
> > > >  					    new_crtc_state, i) {
> > > >  		if (!needs_modeset(new_crtc_state))
> > > > @@ -14362,7 +14369,8 @@ static void
> > > > intel_commit_modeset_disables(struct intel_atomic_state *state)
> > > >  		 * slave CRTCs are disabled first and then master CRTC
> > > > since
> > > >  		 * Slave vblanks are masked till Master Vblanks.
> > > >  		 */
> > > > -		if (!is_trans_port_sync_slave(old_crtc_state))
> > > > +		if (!is_trans_port_sync_slave(old_crtc_state) &&
> > > > +		    !intel_dp_mst_is_slave_trans(old_crtc_state))
> > > >  			continue;
> > > >  
> > > >  		intel_pre_plane_update(state, crtc);
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > index 83ea04149b77..630a94892b7b 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > > @@ -1054,6 +1054,9 @@ struct intel_crtc_state {
> > > >  
> > > >  	/* Bitmask to indicate slaves attached */
> > > >  	u8 sync_mode_slaves_mask;
> > > > +
> > > > +	/* Only valid on TGL+ */
> > > > +	enum transcoder mst_master_transcoder;
> > > >  };
> > > >  
> > > >  struct intel_crtc {
> > > > diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > > b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > > index 7aa0975c33b7..a6237da9ac52 100644
> > > > --- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > > +++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
> > > > @@ -87,10 +87,53 @@ static int
> > > > intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
> > > >  	return 0;
> > > >  }
> > > >  
> > > > +/*
> > > > + * Iterate over all connectors and return the smallest transcoder
> > > > in the MST
> > > > + * stream
> > > > + */
> > > > +static enum transcoder
> > > > +intel_dp_mst_master_trans_compute(struct intel_atomic_state
> > > > *state,
> > > > +				  struct intel_dp *mst_port)
> > > > +{
> > > > +	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
> > > > +	struct intel_digital_connector_state *conn_state;
> > > > +	struct intel_connector *connector;
> > > > +	enum pipe ret = I915_MAX_PIPES;
> > > > +	int i;
> > > > +
> > > > +	if (INTEL_GEN(dev_priv) < 12)
> > > > +		return INVALID_TRANSCODER;
> > > > +
> > > > +	for_each_new_intel_connector_in_state(state, connector,
> > > > conn_state, i) {
> > > > +		struct intel_crtc_state *crtc_state;
> > > > +		struct intel_crtc *crtc;
> > > > +
> > > > +		if (connector->mst_port != mst_port || !conn_state-
> > > > >base.crtc)
> > > > +			continue;
> > > > +
> > > > +		crtc = to_intel_crtc(conn_state->base.crtc);
> > > > +		crtc_state = intel_atomic_get_new_crtc_state(state,
> > > > crtc);
> > > > +		if (!crtc_state->uapi.active)
> > > > +			continue;
> > > > +
> > > > +		/*
> > > > +		 * Using crtc->pipe because crtc_state->cpu_transcoder
> > > > is
> > > > +		 * computed, so others CRTCs could have non-computed
> > > > +		 * cpu_transcoder
> > > > +		 */
> > > > +		if (crtc->pipe < ret)
> > > > +			ret = crtc->pipe;
> > > > +	}
> > > 
> > > Still has the problem that ret==I915_MAX_PIPES if no active crtcs in
> > > the
> > > state.
> > > 
> > > I guess a simple
> > > if (ret == MAX_PIPES)
> > > 	return INVALID;
> > > should do here. Or something similar.
> > 
> > It would never happen, if it is computing state for this MST connector
> > it is active, so it can be master. But okay adding it anyways.
> 
> active != enabled. Pretty sure it will happen.

BTW don't we have a testcase that just enable everything and then
DPMS off everything? Someone should write one if there isn't one.

Patch
diff mbox series

diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c b/drivers/gpu/drm/i915/display/intel_atomic.c
index b7dda18b6f29..0eb973f65977 100644
--- a/drivers/gpu/drm/i915/display/intel_atomic.c
+++ b/drivers/gpu/drm/i915/display/intel_atomic.c
@@ -192,6 +192,20 @@  intel_connector_needs_modeset(struct intel_atomic_state *state,
 									    new_conn_state->crtc)));
 }
 
+struct intel_digital_connector_state *
+intel_atomic_get_digital_connector_state(struct intel_atomic_state *state,
+					 struct intel_connector *connector)
+{
+	struct drm_connector_state *conn_state;
+
+	conn_state = drm_atomic_get_connector_state(&state->base,
+						    &connector->base);
+	if (IS_ERR(conn_state))
+		return ERR_CAST(conn_state);
+
+	return to_intel_digital_connector_state(conn_state);
+}
+
 /**
  * intel_crtc_duplicate_state - duplicate crtc state
  * @crtc: drm crtc
diff --git a/drivers/gpu/drm/i915/display/intel_atomic.h b/drivers/gpu/drm/i915/display/intel_atomic.h
index a7d1a8576c48..74c749dbfb4f 100644
--- a/drivers/gpu/drm/i915/display/intel_atomic.h
+++ b/drivers/gpu/drm/i915/display/intel_atomic.h
@@ -17,6 +17,7 @@  struct drm_device;
 struct drm_i915_private;
 struct drm_property;
 struct intel_atomic_state;
+struct intel_connector;
 struct intel_crtc;
 struct intel_crtc_state;
 
@@ -34,6 +35,9 @@  struct drm_connector_state *
 intel_digital_connector_duplicate_state(struct drm_connector *connector);
 bool intel_connector_needs_modeset(struct intel_atomic_state *state,
 				   struct drm_connector *connector);
+struct intel_digital_connector_state *
+intel_atomic_get_digital_connector_state(struct intel_atomic_state *state,
+					 struct intel_connector *connector);
 
 struct drm_crtc_state *intel_crtc_duplicate_state(struct drm_crtc *crtc);
 void intel_crtc_destroy_state(struct drm_crtc *crtc,
diff --git a/drivers/gpu/drm/i915/display/intel_ddi.c b/drivers/gpu/drm/i915/display/intel_ddi.c
index c9ba7d7f3787..c3ac950e79a8 100644
--- a/drivers/gpu/drm/i915/display/intel_ddi.c
+++ b/drivers/gpu/drm/i915/display/intel_ddi.c
@@ -1899,8 +1899,13 @@  intel_ddi_transcoder_func_reg_val_get(const struct intel_crtc_state *crtc_state)
 		temp |= TRANS_DDI_MODE_SELECT_DP_MST;
 		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
 
-		if (INTEL_GEN(dev_priv) >= 12)
-			temp |= TRANS_DDI_MST_TRANSPORT_SELECT(crtc_state->cpu_transcoder);
+		if (INTEL_GEN(dev_priv) >= 12) {
+			enum transcoder master;
+
+			master = crtc_state->mst_master_transcoder;
+			WARN_ON(master == INVALID_TRANSCODER);
+			temp |= TRANS_DDI_MST_TRANSPORT_SELECT(master);
+		}
 	} else {
 		temp |= TRANS_DDI_MODE_SELECT_DP_SST;
 		temp |= DDI_PORT_WIDTH(crtc_state->lane_count);
@@ -4405,6 +4410,11 @@  void intel_ddi_get_config(struct intel_encoder *encoder,
 		pipe_config->output_types |= BIT(INTEL_OUTPUT_DP_MST);
 		pipe_config->lane_count =
 			((temp & DDI_PORT_WIDTH_MASK) >> DDI_PORT_WIDTH_SHIFT) + 1;
+
+		if (INTEL_GEN(dev_priv) >= 12)
+			pipe_config->mst_master_transcoder =
+					REG_FIELD_GET(TRANS_DDI_MST_TRANSPORT_SELECT_MASK, temp);
+
 		intel_dp_get_m_n(intel_crtc, pipe_config);
 		break;
 	default:
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index fc77829ea958..eb97ad562c96 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -46,6 +46,7 @@ 
 #include "display/intel_crt.h"
 #include "display/intel_ddi.h"
 #include "display/intel_dp.h"
+#include "display/intel_dp_mst.h"
 #include "display/intel_dsi.h"
 #include "display/intel_dvo.h"
 #include "display/intel_gmbus.h"
@@ -11627,6 +11628,7 @@  static void intel_crtc_state_reset(struct intel_crtc_state *crtc_state,
 	crtc_state->hsw_workaround_pipe = INVALID_PIPE;
 	crtc_state->output_format = INTEL_OUTPUT_FORMAT_INVALID;
 	crtc_state->scaler_state.scaler_id = -1;
+	crtc_state->mst_master_transcoder = INVALID_TRANSCODER;
 }
 
 static struct intel_crtc_state *intel_crtc_state_alloc(struct intel_crtc *crtc)
@@ -12484,6 +12486,9 @@  static void intel_dump_pipe_config(const struct intel_crtc_state *pipe_config,
 			      pipe_config->csc_mode, pipe_config->gamma_mode,
 			      pipe_config->gamma_enable, pipe_config->csc_enable);
 
+	DRM_DEBUG_KMS("MST master transcoder: %s\n",
+		      transcoder_name(pipe_config->mst_master_transcoder));
+
 dump_planes:
 	if (!state)
 		return;
@@ -13264,6 +13269,8 @@  intel_pipe_config_compare(const struct intel_crtc_state *current_config,
 	PIPE_CONF_CHECK_I(dsc.dsc_split);
 	PIPE_CONF_CHECK_I(dsc.compressed_bpp);
 
+	PIPE_CONF_CHECK_I(mst_master_transcoder);
+
 #undef PIPE_CONF_CHECK_X
 #undef PIPE_CONF_CHECK_I
 #undef PIPE_CONF_CHECK_BOOL
@@ -14348,7 +14355,7 @@  static void intel_commit_modeset_disables(struct intel_atomic_state *state)
 	u32 handled = 0;
 	int i;
 
-	/* Only disable port sync slaves */
+	/* Only disable port sync and MST slaves */
 	for_each_oldnew_intel_crtc_in_state(state, crtc, old_crtc_state,
 					    new_crtc_state, i) {
 		if (!needs_modeset(new_crtc_state))
@@ -14362,7 +14369,8 @@  static void intel_commit_modeset_disables(struct intel_atomic_state *state)
 		 * slave CRTCs are disabled first and then master CRTC since
 		 * Slave vblanks are masked till Master Vblanks.
 		 */
-		if (!is_trans_port_sync_slave(old_crtc_state))
+		if (!is_trans_port_sync_slave(old_crtc_state) &&
+		    !intel_dp_mst_is_slave_trans(old_crtc_state))
 			continue;
 
 		intel_pre_plane_update(state, crtc);
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index 83ea04149b77..630a94892b7b 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1054,6 +1054,9 @@  struct intel_crtc_state {
 
 	/* Bitmask to indicate slaves attached */
 	u8 sync_mode_slaves_mask;
+
+	/* Only valid on TGL+ */
+	enum transcoder mst_master_transcoder;
 };
 
 struct intel_crtc {
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index 7aa0975c33b7..a6237da9ac52 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -87,10 +87,53 @@  static int intel_dp_mst_compute_link_config(struct intel_encoder *encoder,
 	return 0;
 }
 
+/*
+ * Iterate over all connectors and return the smallest transcoder in the MST
+ * stream
+ */
+static enum transcoder
+intel_dp_mst_master_trans_compute(struct intel_atomic_state *state,
+				  struct intel_dp *mst_port)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
+	struct intel_digital_connector_state *conn_state;
+	struct intel_connector *connector;
+	enum pipe ret = I915_MAX_PIPES;
+	int i;
+
+	if (INTEL_GEN(dev_priv) < 12)
+		return INVALID_TRANSCODER;
+
+	for_each_new_intel_connector_in_state(state, connector, conn_state, i) {
+		struct intel_crtc_state *crtc_state;
+		struct intel_crtc *crtc;
+
+		if (connector->mst_port != mst_port || !conn_state->base.crtc)
+			continue;
+
+		crtc = to_intel_crtc(conn_state->base.crtc);
+		crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
+		if (!crtc_state->uapi.active)
+			continue;
+
+		/*
+		 * Using crtc->pipe because crtc_state->cpu_transcoder is
+		 * computed, so others CRTCs could have non-computed
+		 * cpu_transcoder
+		 */
+		if (crtc->pipe < ret)
+			ret = crtc->pipe;
+	}
+
+	/* Simple cast works because TGL don't have a eDP transcoder */
+	return (enum transcoder)ret;
+}
+
 static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
 				       struct intel_crtc_state *pipe_config,
 				       struct drm_connector_state *conn_state)
 {
+	struct intel_atomic_state *state = to_intel_atomic_state(conn_state->state);
 	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
 	struct intel_dp_mst_encoder *intel_mst = enc_to_mst(&encoder->base);
 	struct intel_dp *intel_dp = &intel_mst->primary->dp;
@@ -154,24 +197,91 @@  static int intel_dp_mst_compute_config(struct intel_encoder *encoder,
 
 	intel_ddi_compute_min_voltage_level(dev_priv, pipe_config);
 
+	pipe_config->mst_master_transcoder = intel_dp_mst_master_trans_compute(state, intel_dp);
+
+	return 0;
+}
+
+/*
+ * If one of the connectors in a MST stream needs a modeset, mark all CRTCs
+ * that shares the same MST stream as mode changed,
+ * intel_modeset_pipe_config()+intel_crtc_check_fastset() will take care to do
+ * a fastset when possible.
+ */
+static int
+intel_dp_mst_atomic_master_trans_check(struct intel_connector *connector,
+				       struct intel_atomic_state *state)
+{
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
+	struct drm_connector_list_iter connector_list_iter;
+	struct intel_connector *connector_iter;
+
+	if (INTEL_GEN(dev_priv) < 12)
+		return  0;
+
+	if (!intel_connector_needs_modeset(state, &connector->base))
+		return 0;
+
+	drm_connector_list_iter_begin(&dev_priv->drm, &connector_list_iter);
+	for_each_intel_connector_iter(connector_iter, &connector_list_iter) {
+		struct intel_digital_connector_state *conn_iter_state;
+		struct intel_crtc_state *crtc_state;
+		struct intel_crtc *crtc;
+		int ret;
+
+		if (connector_iter->mst_port != connector->mst_port ||
+		    connector_iter == connector)
+			continue;
+
+		conn_iter_state = intel_atomic_get_digital_connector_state(state,
+									   connector_iter);
+		if (IS_ERR(conn_iter_state)) {
+			drm_connector_list_iter_end(&connector_list_iter);
+			return PTR_ERR(conn_iter_state);
+		}
+
+		if (!conn_iter_state->base.crtc)
+			continue;
+
+		crtc = to_intel_crtc(conn_iter_state->base.crtc);
+		crtc_state = intel_atomic_get_crtc_state(&state->base, crtc);
+		if (IS_ERR(crtc_state)) {
+			drm_connector_list_iter_end(&connector_list_iter);
+			return PTR_ERR(crtc_state);
+		}
+
+		ret = drm_atomic_add_affected_planes(&state->base, &crtc->base);
+		if (ret) {
+			drm_connector_list_iter_end(&connector_list_iter);
+			return ret;
+		}
+		crtc_state->uapi.mode_changed = true;
+	}
+	drm_connector_list_iter_end(&connector_list_iter);
+
 	return 0;
 }
 
 static int
 intel_dp_mst_atomic_check(struct drm_connector *connector,
-			  struct drm_atomic_state *state)
+			  struct drm_atomic_state *_state)
 {
+	struct intel_atomic_state *state = to_intel_atomic_state(_state);
 	struct drm_connector_state *new_conn_state =
-		drm_atomic_get_new_connector_state(state, connector);
+		drm_atomic_get_new_connector_state(&state->base, connector);
 	struct drm_connector_state *old_conn_state =
-		drm_atomic_get_old_connector_state(state, connector);
+		drm_atomic_get_old_connector_state(&state->base, connector);
 	struct intel_connector *intel_connector =
 		to_intel_connector(connector);
 	struct drm_crtc *new_crtc = new_conn_state->crtc;
 	struct drm_dp_mst_topology_mgr *mgr;
 	int ret;
 
-	ret = intel_digital_connector_atomic_check(connector, state);
+	ret = intel_digital_connector_atomic_check(connector, &state->base);
+	if (ret)
+		return ret;
+
+	ret = intel_dp_mst_atomic_master_trans_check(intel_connector, state);
 	if (ret)
 		return ret;
 
@@ -182,12 +292,9 @@  intel_dp_mst_atomic_check(struct drm_connector *connector,
 	 * connector
 	 */
 	if (new_crtc) {
-		struct intel_atomic_state *intel_state =
-			to_intel_atomic_state(state);
 		struct intel_crtc *intel_crtc = to_intel_crtc(new_crtc);
 		struct intel_crtc_state *crtc_state =
-			intel_atomic_get_new_crtc_state(intel_state,
-							intel_crtc);
+			intel_atomic_get_new_crtc_state(state, intel_crtc);
 
 		if (!crtc_state ||
 		    !drm_atomic_crtc_needs_modeset(&crtc_state->uapi) ||
@@ -196,7 +303,7 @@  intel_dp_mst_atomic_check(struct drm_connector *connector,
 	}
 
 	mgr = &enc_to_mst(old_conn_state->best_encoder)->primary->dp.mst_mgr;
-	ret = drm_dp_atomic_release_vcpi_slots(state, mgr,
+	ret = drm_dp_atomic_release_vcpi_slots(&state->base, mgr,
 					       intel_connector->port);
 
 	return ret;
@@ -240,6 +347,8 @@  static void intel_mst_post_disable_dp(struct intel_encoder *encoder,
 
 	intel_dp->active_mst_links--;
 	last_mst_stream = intel_dp->active_mst_links == 0;
+	WARN_ON(INTEL_GEN(dev_priv) >= 12 && last_mst_stream &&
+		!intel_dp_mst_is_master_trans(old_crtc_state));
 
 	intel_crtc_vblank_off(old_crtc_state);
 
@@ -317,6 +426,8 @@  static void intel_mst_pre_enable_dp(struct intel_encoder *encoder,
 	connector->encoder = encoder;
 	intel_mst->connector = connector;
 	first_mst_stream = intel_dp->active_mst_links == 0;
+	WARN_ON(INTEL_GEN(dev_priv) >= 12 && first_mst_stream &&
+		!intel_dp_mst_is_master_trans(pipe_config));
 
 	DRM_DEBUG_KMS("active links %d\n", intel_dp->active_mst_links);
 
@@ -722,3 +833,14 @@  intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port)
 	drm_dp_mst_topology_mgr_destroy(&intel_dp->mst_mgr);
 	/* encoders will get killed by normal cleanup */
 }
+
+bool intel_dp_mst_is_master_trans(const struct intel_crtc_state *crtc_state)
+{
+	return crtc_state->mst_master_transcoder == crtc_state->cpu_transcoder;
+}
+
+bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state *crtc_state)
+{
+	return crtc_state->mst_master_transcoder != INVALID_TRANSCODER &&
+	       crtc_state->mst_master_transcoder != crtc_state->cpu_transcoder;
+}
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.h b/drivers/gpu/drm/i915/display/intel_dp_mst.h
index f660ad80db04..854724f68f09 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.h
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.h
@@ -6,10 +6,15 @@ 
 #ifndef __INTEL_DP_MST_H__
 #define __INTEL_DP_MST_H__
 
+#include <linux/types.h>
+
 struct intel_digital_port;
+struct intel_crtc_state;
 
 int intel_dp_mst_encoder_init(struct intel_digital_port *intel_dig_port, int conn_id);
 void intel_dp_mst_encoder_cleanup(struct intel_digital_port *intel_dig_port);
 int intel_dp_mst_encoder_active_links(struct intel_digital_port *intel_dig_port);
+bool intel_dp_mst_is_master_trans(const struct intel_crtc_state *crtc_state);
+bool intel_dp_mst_is_slave_trans(const struct intel_crtc_state *crtc_state);
 
 #endif /* __INTEL_DP_MST_H__ */